1,3(2H,4H)-dioxoisoquinoline-4-carboxamides

ABSTRACT

1,3(2H,4H)-Dioxoisoquinoline-4-carboxamides, nuclear unsubstituted and substituted, are prepared by reacting the appropriate homophthalimide with potassium cyanate. Secondary carboxamides are prepared by reacting homophthalimide with appropriate isocyanates, and tertiary carboxamides are prepared by aminolysis of 4-carbalkoxy compounds, which are in turn prepared by alcoholysis of the corresponding 4-carboxanilides. Corresponding 5,6,7,8-tetrahydro compounds are similarly prepared. The various 2-substituted homophthalimides are prepared by reacting homophthalic acid with appropriate amine. The 4carboxamides are anti-inflammatory agents.

United States Patent [191 Kadin [451 May 27, 1975 l,3(2H,4H)-DIOXOISOQUINOLlNE-4- CARBOXAMIDES [75] Inventor: Saul B. Kadin, New London, Conn.

[73] Assignee: Pfizer Inc., New York,

[22] Filed: Feb. 5, 1971 [21] Appl. No.: 113,082

Related US. Application Data [63] Continuation-impart of Ser. No. 649,462, June 28, 1967, abandoned, and a continuation-in-part of Ser. No. 674,664, Oct. 11, 1967, abandoned.

[52] US. Cl.... 260/281; 260/247.2 A; 260/268 BQ;

424/258 [51] Int. CL. C07d 35/38; C07d 35/08; C07d 35/14 [58] Field of Search 260/281, 247.2 A

[56] References Cited UNITED STATES PATENTS 3,726,875 4/1973 Kadin 260/281 Primary ExaminerDonald G. Daus Assistant Examiner--Mark L. Berch Attorney, Agent, or Firm-Connolly and Hutz [57] ABSTRACT l,3(2H,4H)-Dioxoisoquinoline-4-carboxamides, nuclear unsubstituted and substituted, are prepared by reacting the appropriate homophthalimide with potassium cyanate. Secondary carboxamides are prepared by reacting homophthalimide with appropriate isocyanates, and tertiary carboxamides are prepared by aminolysis of 4-carbalkoxy compounds, which are in turn prepared by alcoholysis of the corresponding 4- carboxanilides. Corresponding 5,6,7,8-tetrahydro compounds are similarly prepared. The various 2- substituted homophthalimides are prepared by reacting homophthalic acid with appropriate amine. The 4-carboxamides are anti-inflammatory agents.

8 Claims, N0 Drawings 1 1,3(2H,4H)-DIOXOISOQUINOLINE-4- CARBOXAMIDES CROSSREFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of copending application Ser. No. 649,462, filed June 28, 1967 and now abandoned, and Ser. No. 674,664, filed /1 1/67 and now abandoned.

BACKGROUND OF THE INVENTION This invention relates to a series of novel chemotherapeutic agents and a process for the preparation thereof; in particular, it relates to 1,3(2H,4H)- dioxoisoquinoline-4-carboxamides.

The prior art teaches that primary and secondary carboxamide groups can be substituted for an active hydrogen atom by reacting isocyanic acid or appropriate isocyanate with an organic molecule containing the active hydrogen.

However, this process is not suitable for the preparation of tertiary carboxamides. For this reason, it was desired that l ,3(2H,4H)-dioxoisoquinoline-4- carbalkoxy compounds be prepared, since aminolysis of the esters with appropriate secondary amine would provide a facile synthesis of tertiary carboxamides of the instant invention. Unexpedtedly, treating homophthalimide with ethyl chloroformate under basic conditions, usually a satisfactory procedure for generating a carbethoxy derivative, resulted in an unsatisfactory yield of the desired product.

The prior art also teaches that treating an amide with alcohol is usually a poor method of preparing the corresponding ester. One skilled in the art would expect the interconversion between ester and carboxamide to favor the formation of the carboxamide at the expense of the ester.

SUMMARY OF THE INVENTION The novel carboxamides of this invention are represented by the formulae wherein:

R is selected from the group consisting of hydrogen; alkyl containing up to 6 carbon atoms; alkenyl containing up to 6 carbon atoms; cycloalkyl containing up to 6 carbon atoms; methoxy; hydroxy; benzyloxy; propargyl; 2-furyl; furfuryl; Z-tetrahydrofuryl; tetrahydrofurfuryl; phenyl with up to one substituent selected from the group consisting of fluorine, chlorine, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydroxy; and benzyl with up to one nuclear substituent selected from the group consisting of fluorine, chloride, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydroxy;

R is selected from the group consisting of hydrogen; primary and secondary alkyl containing up to 6 carbon atoms; primary and secondary alkenyl containing up to 6 carbon atoms; primary and secondary alkynyl containing from 3 to 6 carbon atoms; and alkoxyethyl containing up to 4 carbon atoms;

R is selected from the group consisting of hydrogen; alkyl containing up to 6 carbon atoms, alkenyl containing up to 6 carbon atoms; alkynyl containing from 3 up to 6 carbon atoms; cycloalkyl containing up to 6 carbon atoms; carbalkoxyalkyl containing up to 5 carbon atoms; polyfluoroalkyl containing up to 3 carbon atoms, acyl containing up to -4 carbon atoms; benzoyl; tetrahydrofurfuryl; adamantyl; pyridyl; phenyl containing up to 2 substituents each selected from the group consisting of fluorine, chlorine, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, acetyl, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydlroxy; naphthyl with up to l substituent consisting of fluorine, chlorine, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, acetyl, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydroxy; and aralkyl containing up to 8 carbon atoms with up to 1 nuclear substituent selected from the group consisting of fluorine, chlorine, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, acetyl, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydroxy; and

R and R taken together, form a heterocycle selected from the group consisting of pyrrolidine, piperidine, hexamethyleneimine, morpholine, piperazine, N-methylpiperazine and N-phenylpiperazine;

provided that R is always hydrogen when R is selected from the group consisting of tertiary alkyl, tertiary alkenyl, tertiary alkynyl, nitro-substituted phenyl, nitro-substituted aralkyl, and acyl; and

X and X are each selected from the group consisting of hydrogen, fluorine, chlorine, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, acetyl, trifluoromethyl, nitro, amino,

methylsulfonyl, trifluoromethylsulfonyl, dimethylsulwherein X, and X are as aforesaid and R is selected from the group consisting of alkyl containing between 2 and 6 carbon atoms; alkenyl containing up to 6 carbon atoms; cycloalkyl containing up to 6 carbon atoms; methoxy; propargyl; 2-furyl; furfuryl; 2- tetrahydrofuryl; tetrahydrofurfuryl; phenyl with one substituent selected from the group consisting of fluorine, chlorine, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydroxy; and benzyl with one nuclear substituent selected from the group consisting of fluorine, chlorine, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydroxy.

Certain of the hereinbefore specified carboxamides, particularly those wherein R is other than hydrogen, are most easily prepared by aminolysis of novel 4- carbalkoxy compounds of the formula wherein R is selected from the group consisting of hydrogen; alkyl containing up to 6 carbon atoms; alkenyl containing up to 6 carbon atoms; cycloalkyl containing up to 6 carbon atoms; methoxy; hydroxy; benzyloxy; propargyl; 2-furyl; furfuryl; Z-tetrahydrofuryl; tetrahydrofurfuryl; phenyl with up to one substituent selected from the goup consisting of fluorine, chlorine, bromine,

alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydroxy; and benzyl with up to one nuclear substituent selected from the group consisting of fluorine, chlorine, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydroxy; R is alkyl containing up to 6 carbon atoms; and X and X are each selected from the group consisting of hydrogen, fluorine, chlorine, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, acetyl, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimelthylsulfonamido, acetamido and hydroxy.

However, attempts to synthesize said carbalkoxy compounds by conventional methods have resulted in unsatisfactory procedures. A surprisingly satisfactory process is achieved by 'alc'oholysis of hereinbefore specified carboxamides'wherein R is selected from the group consisting of hydrogen; alkyl containing up to 6 carbon atoms; cycloalkyl containing up to 6 carbon atoms; methoxy; hydroxy; benzyloxy; propargyl; 2- furyl; furfuryl; 2-tetrahydrofuryl; tetrahydrofurfuryl; phenyl with up to one substituent selected from the group consisting of fluorine, chlorine, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydroxy; and benzyl with up to one nuclear substituent selected from the group consisting of fluorine, chlorine, bromine, alkoxy containingv up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydroxy; R is hydrogen; and R is phenyl with up to two substituents each selected from the group consisting of fluorine, chlorine, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, acetyl, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydroxy. Thus, the carboxanilides of the instant invention are useful as synthetic intermediates in the preparation of other useful compounds.

The novel 5,6,7,8-tetrahydro-1 ,3(2I-I,4H dioxoisoquinolnne-4-carboxamides of formula II are prepared in the same manner as are the corresponding unsubstituted compounds of formula I, using the appropriate tetrahydro substrates.

The novel carboxamides of the instant invention are useful as antiinflammatory agents.

DETAILED DESCRIPTION OF THE INVENTION wherein X X and R areas aforesaid, are most easily prepared by treating a homophthalic acid with an amine of the formula R N I-I Amines R Nl-I in turn, are either known compounds or can be readily synthesized by methods familar to those skilled in the art. 'It is preferable to use at least a molar equivalent amount of said amine in v the reaction with homophthalic acid, and often an excess amount is benefical. The process of mixing the two materials is usually exothermic, but additional heat is necessary to produce the imide. Heating the mixture with an oil bath to about l75-275C. for up to 2 hours will accomplish the desired condensation although the reaction with certain amines has, been effected in as little as 40 minutes. Water is produced as a by-product of the condenstion but is driven off by the high reaction temperature. The desired product can be isolated in a variety of ways known to those skilled in the art. For example, the reaction mixture can be poured while hot into an excess of alcohol, which is then concentrated and cooled to cause crystallization of product. Also, the reaction mixture can be allowed to cool and solidify, with the product then isolated by crystallization.

The corresponding 5,6,7,8-tetrahydro-1,3(2H,4H)- dioxoisoquinolines of the formula wherein R is as aforesaid, are similarly prepared and are used in the preparation of tetrahydrocarboxamides of formula II in a manner analogous to hereinafter discussed conversion of homophthalimides to carboxamides of formula I.

The various primary carboxamides, wherein R and R are each hydrogen, are prepared by treating aforesaid homophthalimides and inorganic cyanates such as potassium cyanate. The reaction is conducted in a reaction-inert solvent. It may be desirable to dissolve each of the two substrate materials first and then to combine the two solutions to effect the reaction; it is not necessary that the same solvent be used for each substrate so long as the solvents are mutually miscible. Thus, the cyanate salt can be dissolved in water and the homophthalimide in dimethylformamide, dimethylsulfoxide, acetone or alcohol. It is desirable to use at least about a molar equivalent amount of cyanate, and best results are often obtained by using an excess of that reagent. The reaction mixture is heated, using a steam bath or other appropriate heat source. Reaction time is not critical but the conversion is usually complete within about 2-4 hours, after which time the product is isolated. A convenient means of isolation is to add the reaction mixture to an excess of acidified ice water, which causes the product to precipitate.

The. various primary tetrahydrocarboxamides are prepared by similarly treating the 5,6,7,8-tetrahydrol,3(2H,4H)-dioxoisoquinolines. In like manner, each of the following synthetic procedures, which are directed to carboxamides of formula I, may be used with a corresponding tetrahydro substrate for the preparation of carboxamides of formula II.

The secondary carboxamides of the instant invention, wherein R is hydrogen and R is not hydrogen, may be synthesized by treating aforesaid homophthalimides in basic solution with anappropriate isocyanate of the formula R -NCO wherein R corresponds to the nitrogen substituent of the desired carboxamide. Common reaction-inert organic solvents, such as tetrahydrofuran, dimethylformamide and dimethylsulfoxide, are acceptable. It is preferable that a slight molar excess of base, such as triethylamine, be added to the solvent. Many of aforesaid isocyanates R NCO are known compounds and the others may be synthesized by methods known to those skilled in the art. It is preferable to use at least about a molar equivalent amount of isocyanate and best results are usually obtained by using an excess. The mixture may be heated to effect the reaction. Although temperatures below that of reflux may be used, they require longer reaction times; at reflux temperature, the reaction may be complete within a time ranging from several minutes up to about 24 hours, depending upon the particular carboxamide being prepared. The product is easily recovered by pouring the reaction mixture into an excess of ice water containing a slight excess of hydrochloric acid; the carboxamide precipitates and is collected by filtration.

The tertiary carboxamides, wherein neither R nor R is hydrogen, cannot be prepared by the isocyanate procedure since the isocyanate group cannot accomodate a disubstituted nitrogen atom. Therefore, these compounds are conveniently prepared by aminolysis of 4- carbalkoxy compounds with secondary amines of the formula RE-NH,

wherein R and R correspond to the particular nitrogen substituents of the desired carboxamide. This aminolysis procedure may also be used advantageously to prepare certain of the secondary carboxamides of the instant invention. When synthesis of any of aforesaid isocyanates R -NCO is inconvenient or difficult, the 4-carbalkoxy compounds may be treated with primary amines of the formula R -Nl-l to produce the secondary carboxamide, thus avoiding the need to synthesize the corresponding isocyanate. For example, a 4- carbalkoxy compound can be treated with adamantylamine to prepare the 4-carboxamide wherein R is hydrogen and R is the adamantyl moiety. The aminolysis is conducted in a reaction-inert solvent such as xylene, preferably using a slight molar excess of amine with respect to the 4-carbalkoxy compound. The reaction mixture is refluxed for about 0.5-4 hours. A convenient means'of isolating the product is to distill off a portion of the solvent; when the temperature of the solvent vapors in the distilling head is within about one or two degrees of the temperature of the reaction mixture, the mixture is allowed to cool and the product precipitates.

Attempts to synthesize aforesaid 4-carbalkoxy compounds by a conventional procedure were not successful. It would normally be expected by one skilled in the art that treating a homophthalimide with ethyl chloroformate and sodium hydride would generate the corresponding 4-carbethoxyhomophthalimide, since these reagents are commonly used to generate a 4- carbethoxy substituent at the site of an active hydrogen atom. In fact, the 4-carbethoxy derivative was only generated with difficulty and in an unsatisfactory yield.

Surprisingly, it has been found that carboxamides of the instant invention wherein R is hydrogen and R is substituted or unsubstituted phenyl, i.e., 4- carboxanilides, can be refluxed in alcohol to form the corresponding ester of said alcohol in yields in excess of This effective conversion of a carboxamide to a carbalkoxy compound is unexpected since, even in the presence of a substantial excess of alcohol, one skilled in the art would normally expect the amide to predominate in the equilibrium existing between ester and carboxamide. For example, S. M. McElvain, Characlerization of Organic Compounds, rev. ed. (1953), p. 189, teaches that anilides may be recrystallized from alcohol, indicating that conversion of the amide to the ester is not readily achieved. Furthermore,refluxing for 8 hours on ethanolic solution of acetoacetanilide, an anilide structurally similar to the 4-carboxanilides of the instant invention, does not result in the formation of the corresponding ester. However, heating the carboxanilides of the instant invention in an excess of alcohol containing up to 6 carbon atoms at a temperatue between about 50C. and reflux temperature provides an effective and efficient means of preparing the desired ester. The reaction time is not critical, although at least one hour is preferable. Of course, a reaction temperature below that of reflux will require a longer reaction time to accomplish the same degree of conversion as is possible at reflux; therefore, the higher reaction temperature is usually preferred. Although any carboxanilide of the instant invention may be used to produce the desired esters, particularly good results have been observed by using carboxanilides substituted at the ortho position with groups such as chlorine and methoxy.

It is noted that aforesaid carboxanilides can also be used advantageously in the preparation of other carboxamides, without formation of the esters as an intermediate. Heating molar equivalent amounts of a carboxanilide and a primary or secondary amine in a reaction-inert solvent, such as xylene, results in the substitution of the amine for the aniline moiety. An excess of the amine is often beneficial. Reflux temperature is preferred, although lower temperature may be used with correspondingly longer reaction times. Upon cooling, the desired product precipitates and is collected by filtration. Treating 2'-chloro-2-methyl-l,3(2H,4H)- dioxoisoquinoline-4-carboxanilide with benzyl amine to obtain the corresponding N-benzyl carboxamide is an illustration of this procedure.

As indicated hereinbefore, the 1,3(2H,4H)- dioxoisoquinoline-4-carboxamides of the instant invention are useful as anti-inflammatory agents. These compounds are of value in alleviating swelling and inflammation which are symptomatic of rheumatism and arthritis and of other disorders which are responsive to treatment with anti-flammatory agents. Either as individual therapeutic agents or as mixtures of theraputic agents, they may be administered alon, but are generally administered with a pharmaceutical carrier selected on the basic of the chosen route of administration and standard pharmaceutical practice. For example, they may be administered orally in the form of tablets or capsules containing such excipients as starch, milk sugar. or certain types of clay, etc. They may be administered orally in the form of elixirs or oral suspensions with the active ingredients combined with emulsifying and/or suspending agents. They may be injected parenterally, and for this use they, or appropriate derivatives, may be prepared in the form of sterile aqueous solutions. Such aqueous solutions should be suitably buffered, if necessary, and should contain other solutes such as saline or glucose to render them isotonic.

The dosage required to reduce inflammation or swelling in arthritic and rheumatic subjects would be determined by the nature and extent of the symptoms. Generally, small doses will be administered initially, with a gradual increase in the dosage until the optimum level is determined. It will generally be found that when the composition is administered orally, larger quantities of the active ingredient will be required to produce the same level as produced by a small quantity administered parenterally. in general, from about 0.02 to about 200 mg. of active ingredient per kilogram of body weight, administered in single or multiple dose units, will effectively reduce inflammation and swelling.

Particularly effective as anti-inflammatory agents are those carboxamides of the instant invention of formula I wherein R is selected from the group consisting of hydrogen and methyl, R is hydrogen, and R is phenyl with up to two substituents each selected from the group consisting of fluorine, chlorine, bromine, alkoxy containing up to 2 carbon atoms, alkyl containing up to 3 carbon atoms, acetyl, trifluoromethyl, nitro, amino, methylsulfonyl, trifluoromethylsulfonyl, dimethylsulfonamido, acetamido and hydroxy, and X and X are each hydrogen. Among these compounds, 2-methyll ,3(2H,4H)-dioxoisoquinoline-4-carboxanilide, 4'- chloro-2-methyl-l ,3(2H,4H )-dioxoisoquinoline-4- carboxanilide, 4'-chlorol ,3(2H, 4H)- dioxoisoquinoline-4-carboxanilide, 4-fluoro-2-methyll ,3(2H,4H)-dioxoisoquinoline-4-carb0xanilide and 2- 4 -dichloro-2methyl-1 ,3 (2H APB-dioxoisoquinoline- 4-carboxanilide are especially preferred.

It is noted that a common characteristic of many antiinflammatory agents is that they contain an active hydrogen atom. Each of the 4-carboxamides of the instant invention shares this property and is an effective proton source, with the active hydrogen being located at the 4-position.

A standard procedure for detecting and comparing anti-inflammatory activity of compounds is the carrageenin rat foot edema test, whereby unanesthetized adult male albino rats of 150-190 g. body weight are each numbered, weighed and marked with ink on the right lateral malleolus. One hour after administration of the drug by gavage, edema is induced by injection of 0.05 ml. of 1% solution of carrageenin into the plantar tissue of the marked paws. Immediately thereafter, the volume of the injected paw is measured. The increase in volume three hours after the injection of carrageenin constitutes the individual response. Compounds are considered active if the difference in response between a control and the drug being tested is significant. Standard compounds are phenylbutazone at 33 mg/kg and acetylsalicylic acid at 100 mg/kg, both with oral administration.

The following examples are given to more fully illustrate the instant invention. They are not the only possible embodiments of the invention and are not to be considered as a limitation on the scope thereof.

EXAMPLE I 2-( m-Chlorophenyl )isoquinoline-l ,3 2H,4H )-dione A mixture of homophthalic acid (45.0 g., 0.25 mole) and m-chloroaniline (31.8 g., 0.25 mole) was heated by an oil bath to ll80C. for 2 hours. When removed from the oil bath, the reaction mixture solidified and was recrystallized twice from ethanol/ethyl acetate, giving 2-(m-chlorophenyl)-isoquinolinel ,3(2H,4H dione, 36.0 g. (58% yield), m.p. l60l6lC.

Anal. Calcd for C H CINO C, 6.3; H, 3.68; N, 5.l6. Found: C, 65.71; H, 3.79; N, 5.23.

EXAMPLE II 2-Allylisoquinoline-l ,3 2H,4H )-dione A mixture of homophthalic acid (9.0 g., 0.05 mole) EXAMPLE III 2-Isopropylisoquinoline-1 ,3 2H, 4H )-dione A mixture of homophthalic acid (90 g., 0.5 mole) and isopropylamine (59 g., 1 mole) was heated by an oil bath to l75180C. for 90 minutes. The hot mix- .ture was then poured into 600 ml. of ethanol, treated with carbon black and filtered. The mixture was concentrated toabout 300 ml. and slowly cooled to room temperature. 2-Isopropylisoquinoline-1,3(2H, 4H)- dione precipitated and was collected by filtration, 46 g. (45% yield), m.p. 8688C.

Anal. Calcd for C H, O N: C, 70.91; H, 6.45; N, 6.89. Found: C, 70.93; H, 6.43; N, 6.92.

EXAMPLE IV Z-Methoxyisoquinolinel ,3 2H,4H )-dione A mixture of homophthalic acid (9.0 g., 0.05 mole) and methoxyamine hydrochloride (4.25 g., 0.05 mole) in 125 ml. of xylene was refluxed for 90 minutes, with water collected in Dean Stark trap as it formed. The reaction mixture was cooled and concentrated by vacuum to one half its original volume, then diluted with ethylacetate, washed with water and dried over sodium sulfate. Recrystallization from isopropanol and ethanol, followed by drying at 100C. for 4 hours yielded pale pink crystals of 2-methoxyisoquinoline- 1,3(2H,4H)-dione, m.p. 1l3-l14C.

Anal. Calcd for C H NO C, 62.82; H, 4.74; N, 7.33. Found: C, 62.91; H, 4.77; N, 7.16.

EXAMPLE V The following products are prepared by the procedure of Example I by substituting an appropriate amine in place of said m-chloroaniline:

2-I-Iexylisoquinoline-l ,3 2H,4H )-dione 2-Cyclopropylisoquinoline- 1 ,3 2H ,4H )-dione 2-Cyclohexylisoquinoline-l ,3 2H ,4H )-dione 2-Propargylisoquinoline-1,3(2H,4H)-dione 2-( 2 '-Fury1 )isoquinoline-l ,3 2H ,4H )-dione 2-( 2 '-Tetrahydrofuryl )isoquinolinel ,3 2H ,4H

dione 2-Furfurylisoquinoline-l ,3 2H,4H )-dione 2-Tetrahydrofurfurylisoquinoline-1, 3 2H ,4H )-dione 2-( oFluorophenyl )isoq uinoline-l ,3 2H ,4H )-dione 2-( p-Br'omophenyl )isoq uinoline-l ,3 2H ,4H )-dione 2-( p-Ethoxyphenyl )isoquinoline-l ,3 2H ,4H )-dione 2-( m-Isopropylphenyl isoquinolinel l, 3 2H,4H

dione 2-( o-Methylphenyl )isoquinoline-l ,3 2H,4H )-dione 2-( m-Trifluoromethylphenyl )isoquinoline- Z-(m-Nitrophenyl)isoquinolinel 1,3( 2H,4H)-dione 2-(p-Aminophenyl)isoquinoline-1 ,3 2H ,4H )-dione 2-( o-Methylsulfonylphenyl )isoquinolinel,3(2l-I,4H)-dione 2-( m-Trifluoromethylsulfonylphenyl )isoquinoline- 10 2-(m-Dimethylsulfonamidophenyl )isoquinolinel,3(2H,4H)-dione 2-(m-Dimethylsulfonamidophenyl)isoquinoline- 1,3(2H,4H)-dione 2-(p-Acetamidophenyl)isoquinoline-l ,3(2H,4H

dione 2-(o-Hydroxyphenyl)isoquinolinel 1 ,3(2H,4H

dione 2-(o-Fluorobenzyl)isoquinolinel1,3(2H,4H)-dione 2-(p-Bromobenzyl )isoquinolinel ,3(2H,4H )-dione 2-(p-Ethoxybenzyl)isoquinoline-l ,3(2H,4H)-dione 2-(m-Isopropylbenzyl)isoquinoline l 1 ,3 2H ,4H

dione 2-(0-Methylbenzyl )isoquinolinel ,3(2H,4H )-dione 2-(m-Trifluoromethylbenzyl )isoquinolinel,3(2H,4H)-dione 2-(m-Nitrobenzyl)isoquinoline-1,3(2H,4H)-dione 2-(p-Aminobenzyl)isoquinoline-1,3(2H,4H)-dione 2-(o-Methylsulfonylbenzyl)isoquinolinel,3(2H,4H)-dione 2-(m-Trifluoromethylsulfonylbenzyl)isoquinolinel,3(2H,4H)-dione 2-(m-Dimethylsulfonamidobenzyl)isoquinolinel,3(2H,4H)-dione 2-(p-Acetamidobenzyl )isoquinolinel ,3 2H,4H)-

dione 2-(o-Hydroxybenzyl)isoquinoline-l ,3(2H,4H)-dione EXAMPLE VI 1,3(2H,4H)-Dioxo-2-methylisoquinoline-4- carboxamide A solution of potassium cyanate (2.84 g., 0.035 mole) in 10 ml. of water was added with stirring, over a 30 minute period, to a solution of I,3(2I-I,4H)-dioxo- Z-methylisoquinoline (4.4 g., 0.025 mole) in 20 ml. of dimethylformamide which was heated over a steam bath. The resulting solution was heated for an additional 2 hours and then poured into an excess of ice water containing 10 m1. of 6N hydrochloric acid. The resulting precipitate was filtered, dried and recrystallized from acetonitrile to give white needles of l,3(2H,- 4H)-dioxo-2-methylisoquinoline-4-carboxamide, 3.0 g (56% yield), m.p. 214 215C.

Anal. Calcd for C H N 0 C, 60.65; H, 4.62; N, 12.84. Found: C, 60.40; H, 4.85; N, 13.08.

EXAMPLE VII 1,3 2H,4H )-Dioxo-2-phenylisoquinoline-4- carboxamide The procedure of Example VI was repeated, using l,3(2H,4H)-dioxo-2-phenylisoquinoline in place of said Z-methyl derivative, to prepare l,3(2H,4H)-dioxo- Z-phenylisoquinoline-4-carboxamide, m.p. l92194C.

Anal. Calcd for C H N O C, 68.56; H, 4.32;. N, 10.00. Found: C, 68.32; H, 4.41; N, 10.33.

EXAMPLE VIII The procedure of Example VI is repeated, using products of Example V in place of said l,3(2H,4I-I)- dioxo-2-methylisoquinoline, to prepare the following compounds:

1 ,3(2H,4H)-Dioxo-2-hexylisoquinoline-4- carboxamide l ,3(2H,4H)-Dioxo-2-cyclopropylisoquinoline-4- carboxamide Anal: Calcd Found R R M.P.,C. C H N C H N CH n-butyl 176-177 65.67 6.61 10.21 65.46 6.67 10.16

m-chlorobenzoyl 201-203(dec.) 65.95 3.61 6.69 65.61 3.59 6.67

phenyl CH carbethoxy- 180-182 59.20 5.30 9.21 58.78 5.40 9.18

methyl EXAMPLE XII dimethylsulfoxide. After stirring for 2 hours, the solu- 10 tion was poured into an excess of ice water containing The procedure of Example IX was repeated, using 5 ml. of hydrochloric acid. The resulting precipitate appropriately substituted substrates, to produce the folwas collected by filtration, washed with water, dried lowing compounds: and recrystallized from acetronitrile to give 1,3(2H,4-

Anal: Calcd Found R, x M.p.,C. c H N c H N CH H 246-247(C1EC.) 69.37 4.79 9.52 69.52 4.81 9.51 CH 2'-Cl 211-213(dec.) 62.10 3.98 8.52 61.99 3.97 8.47 CH3 3'Cl 203-205 62.10 3.98 8.52 61.82 4.05 8.64 CH; 4'-Cl 213-214(dec.) 62.10 3.98 8.52 62.22 3.91 848 CH; 3'CH 224-225(dec.) 70.1 1 5.23 9.09 69.97 5.15 9.03 CH 4'--CH 232-234(dec.) 70.1 1 5.23 9.09 69.89 5.24 9.14 CH; 2'OCH,-, 197-198 6665 4.97 8.64 66.69 5.02 8.74 CH3 4'OCH3 222-224 66.65 4.97 8.64 66.84 5.09 8.64 CH3 2'OC2H5 220-221 67.44 5.36 8.28 67.74 5.14 8.33 CH3 4'-OC2H5 212-214 67.44 5.36 8.28 67.83 5.64 8.41 m-chloro- H 227-229 67.61 3.84 7.17 67.66 4.08 7.11

hen 1 56.1231 H 222-223(dec.) 74.58 4.90 7.56 74.80 4.93 7.60 allyl H 205- 206 71.23 5.04 8.75 71.03 4.95 8.78

EXAMPLE XIII H)-di0xoisoquinoline-4-(N-methyl)carboxamide, m.p.

254255C. 1,3(2H,4H)-Dioxoisoquinoline-4-(N-methyl)carboxa- 40 Anal. Calcd for C H N o z C, 60.54; H, 4.62; N,

mide 12.84. Found: C, 60.79; H, 4.66; N, 12.56

To a stirred mixture of 1,3(21-1,4H)- EXAMPLE XIV dioxoisoquinoline (4.0 g., 0.025 mol) and triethylam- The procedure of Example XIII was repeated, using ine (2.6 g., 0.026 mole) in 10 ml. of dimethylsulfoxide 45 equivalent amounts of appropriate substrates in place was added dropwise, over a 5 minute period, a solution of said isoquinoline and said. methylisocyanate, to proof methylisocyanate (1.5 g., 0.026 mole) in 10 ml. of duce the following compounds:

O\/NH R5 '/\\)\\===O i 1 N k/ l Anal: Calc'd Found R R3 M.p.,C. C H N C H N H ethyl 252-253(c1ec.) 62.06 5 21 12.07 62.34 5.13 12.08 H cyclohexyl 223-225(dec.) 67.1 1 6.34 9.79 67.47 6.51 10.12 methyl ethyl 230-231 63.40 5.73 11.38 63.41 5.68 11.52 methyl n-propyl 209-210 64.60 6.20 10.76 64.71 6.10 10.90 methyl cyclohexyl 221-223(dec.) 67.98 6.71 9.33 68.29 6.39 9.60 methyl Methyl 250-251(dec.) 62.06 5.21 12.07 62.29 5.13 11.87 m-chloroethyl 21 1-212 63.07 4.41 8.17 62.97 4.32 8.17 phenyl m-ch1oron-propyl 195-197 63.95 4.80 7.85 64.06 4.73 7.86 phen l m-chl oro cyclohexyl 237-238(dec.) 66.58 5.33 7.06 66.85 5.51 7.39 phenyl m-chlorocarbethoxy- 174-175 59.93 4.28 6.99 60.19 4.32 6.78 phenyl methyl isopropyl ethyl 173-174 65.67 6.61 10.21 65.65 6.62 10.17

allyl ethyl 189-191 66.16 5.92 10.29 66.30 5.98 10.21

EXAMPLE xv k K N R from xylene, giving l,3(2H,4H)-Dioxo-2- methylisoquinoline-4-(N-benzyl)carboxamide, m.p. 17l173C. (dec.).

Anal. Calcd for C H N O z C, 70.11; H, 5.23; N,

5 9.09. Found: C, 70.12; H, 5.38; N, 9.37.

Anal: Calcd Found R X M.p.,C. C H N C H N CH, 2'CH, 224-225(dec.) 70.11 5.23 9.09 70.45 5.19 917 CH, 2',5-d|C1 222-223(dec.) 56.21 3.33 7.71 56.08 3.23 7.49 H 2'-Cl 223-224(dec.) 61.06 3.52 8.90 61.47 3.15 8.99 H 3-Cl 232-234(dec.) 61.06 3.52 8.90 60.94 3.43 9.27 H 4-C1 243245(dec.) 61.06 3.52 8.90 61.11 3.31 9.04 H 2-CH 242243(dec.) 69.37 4.79 9.52 69.69 4.84 9.40 H 3'CH 232-233(dec.) 69.37 4.79 9.52 69.37 4.87 9.65 H 4'-CH 236-237(dec.) 69.37 4.79 9.52 69.39 4.61 9.50 H 2'-OCH 2102l 1(dec.) 65.80 4.55 9.03 66.09 4.59 9.13 H 4'OCH 237-238(dec.) 65.80 4.55 9.03 65.96 4.48 8.92 m-CLC H 2,5-diCl 222-223(dec.) 56.21 3.33 7.71 56.08 3.23 7.49 H OC H, 232-233(dec.) 66.65 4.97 8.64 66.57 4.92 8.86 H 2OC H 203-205(dec.) 66.65 4.97 8.64 66.29 4.92 8.86

EXAMPLE XVI 1,3(2H,4H )-Dioxo-2-methylisoquinoline-4-( N- EXAMPLE XVII The procedure of Example XVI was repeated, using benzyl)carboxamide equivalent amounts of appropriate amines in place of A mixture of l,3(2H,4H)-Dioxo-2- said benzylamine, to produce the following commethylisoquinoline-4-carbox-o-chloroanilide (8.2 g., pounds:

/ \N/ Y 1. 1 N l/ 5 Anal: Calcd Found R R M.p.,C. C H N C H N (CH 164165 67.11 6.34 9.79 67.15 6.27 v 9.84 (CH O(CH 160-161 62.49 5.59 9.72 62.52 5.51 9.76 H 2 allyl 206-207 65.10 5.46 10.85 65.10 5.48 10.91 H 4CH O 172-176(dec.) 67.44 5.36 8.28 67.75 5.60 8.52

benzyl H 3,4-diCl- 224-225 57.31 3.74 7.43 57.30 3.83 7.60

benzyl H B-phenethyl 201-202 70.79 5.63 8.69 70.67 5.58 8.71

0.025 mole), prepared by the procedure of Example EXAMPLE XVIII and benzylamine g, 0925 mole) in 100 55 The procedure of Example XVI was repeated, using of xylene was refluxed for 6 hours, after which time the mixture was allowed to cool. The resulting precipitate was collected by filtration, dried and recrystallized equivalent amounts of appropriate amines in place of said benzyl amine, to produce the following compounds:

17 y 18 Continued Anal: Calcd Found X H M.p.,C. C H N C H N 3,4-diCI-I 214-216(dec.) 70.79 5.63 8.69 71.06 5.77 8.83 3',4'-diCl 219-220(dec.) 56.21 3.33 7.71 56.39 3.29 7.87 3'-CF 188-190(dec.) 59.67 3.62 7.73 59.76 3.68 7.52 2,4'-diOCH 203-204 64.40 5.12 7.91 64.40 5.15 7.84 2',5'diOCl-l;, 183-184 64.40 5.12 7.91 64.45 5.11 7.84

EXAMPLE XIX i-Propyl l,3(2H,4H)-Dioxo-2-hydroxyisoquinoline- Ethyl 4-carboxylate 1,3(2H,4H)-Dioxo-2-methylisoquinoline-4- l'pmpyl carboxylate I benzyl0xy1soqumol1ne-4-carboxylate i-Propyl 1,3(2H,4H)-D1oxo-2-(o- A miXtllfe 0f A fluorophenyl )isoquinoline-4-carboxylate methylisoquinoline-4-carbox-o-chloroanilide (16.5 g., i-p 1 1 3 2 4 2 0.05 mole), prepared by the procedure of Example XII, bromophenyl)isoquinoline 4 carboxylate in 125 ml. of absolute ethanol was refluxed fro 4 hours. 1 1 3 2H 4H Di 2 The original white suspension became a clear yellow ethoxyphenyl)1S0quinoline 4 carboxylate solution after about 45 minutes, which darkened 1 1 3 2 4 Di -2- slightly during the period of additional heating. The soisopl-opylphenyl)isoquinoline 4 carboxylate lution was then concentrated to one half of its original n Hexy1 13(2H,4H) DiOXO 2 (O volume and cooled slowly. The resulting precipitate methylphenyl)isoquin0line 4 carboxylate was collected by filtration and dried to give ethyl 1,3(2- n HeXy] 13(2H4H) Diom 2 (m H,4H )-dioxo-2-methylisoquinoline-4-carboxylate, 1 1.5 trifiuoromethylphenyl)isoquinoline 4 carboxylate g. (94% yield), m.p. l13-l15C. H 1 2 4 2 Analcalcd for C18H13NO4: 63-15; H, 530; N nitrophenyl)isoquinoline-4-carboxylate 5.67. Found: C, 63.07; H, 5.33; N, 5.65. 30 i y1 1 3 2 4 2 p EXAMPLE XX aminophenyl)isoquinoline-4-carboxylate I i-Butyl l,3(2H,4H)-Dioxo-2-(o- Ethyl 1,3 2H4H )'Dloxolsoqumolme'4'carboxylate methylsulfonylphenyl )isoquinoline-4-carboxylate A mixture of 2'-chloro-1,3(2H,4H)- i-Butyl l,3(2H,4I-I)-Dioxo-2-(mdioxoisoquinoline-4-carboxanilide (67.0 g., 0.25 trifluoromethylsulfonylphenyl)-isoquino1ine-4- mole), in one liter of absolute ethanol is refluxed for 5 carboxylate hours, cooled and filtered. The precipitate is air dried i-Butyl l,3(2H,4H)-Dioxo-2-(mand recrystallized from acetic acid to give ethyl 1,3(2- dimethylsulfonamidophenyl)isoquinoline-4- H,4I-I)-dioxois0quinoline-4-carboxylate, m.p. carboxylate 238240C. 4O i-Butyl l,3(2H,4H)-Dioxo-2-(p- Anal. Calcd. for C H 1NO4I C, 61.80; H, 6; acetamidophenyl)isoquinoline-4-carboxylate 6.01. Found: C, 61.51; H, 4.81; N, 6.06. Ethyll,3(2H,4H)-Di 2 hydroxyphennyl)isoquinoline-4-carboxylate EXAMPLE XXI Ethyl l,3(2H,4l'l)-D1OXO2-(O- The Procedure of Example XIX is repeated, using fluorobenzyl)isoquinoline-4-carboxylate equivalent amounts of appropriately substituted car- Eth l 1,3(2H,4H)-Di0xo-2-(pboxanilides and appropriate alcohol in place Of said bromobenzyl)isoquinolinel-carboxylate carbox-o-chloranilide and said ethanol, to produce the Ethyl 1,3(2H,4H)-Di -2- following compounds: ethoxybenzyl)isoquinoline-4-carboxylate Methyl 1,3(2H,4I-I)-Dioxo-2-hexylisoquinoline-4- Ethyl l,3(2H,4l-I)-Di -2- carboxylate isopropylbenxyl)isoquinoline-4-carboxylate Methyl l,3(2H,4H)-Di0X0-2- Ethyl 1,3(2H,4H )-Dioxo-2-(- cyclopropylisoquinoline-4-carboxylate Methybenzyl)isoquinoline-4-carboxylate Methyl l,3(2H,4H)-Dioxo-2-cyclohexylisoquinoline- Eth l 1 3(2H,4H) Di -2 4-carboxylate trifluoromethylbenzyl)isoquinoline-4-carboxylate Methyl 1,3(2H,4II)-Dioxo-2-propargylisoquinoline- E h l 1 3(2H 4H)-Di 2 4-carboxylate nitrobenzyl )isoquinoline-4-carboxylate Methyl l,3(2H,4H)-Dioxo-2-(2'-fury1)is0quinoline- Ethyl 1,3(2H,4H)-Dioxo-2-(p- 4-carboxylate aminobenzyl)isoquinoline-4-carboxylate i-Propyl 1,3(2H,4I-I)-Dioxo-2-(2'- 6O Ethyl 1,3(2I-I,4I-I)-Dioxo-2-(otetrahydrofuryl)isoquinoline-4carboxylate methylsulfonylbenzyl)isoquinoline-4-carboxylate i-Propyl l,3(2I-I,4I-I)-Dioxo-2-(furfuryl)isoquinoline- Ethyl 1,3(2H,4I-I)-Dioxo-2-(m- 4-carboxylate trifluoromethylsulfonylbenzyl)isoquin0line-4- i-Propyl l,3(2l-I,4H)-Dioxo-2- carboxylate (tetrahydrofurfuryl)isoquinoline-4-carboxylate i-Propyl l,3(2I-I,4I-I)-Dioxo-2-methoxyisoquinoline- 4-carboxylate Ethyl l,3(2I-l,4I-I)-Dioxo-2-(mdimethylsulfonamidobenlzyl )isoquinoline-4- carboxylate 1 9 Ethyl 1,3(2H,4h)-Dioxo-2-(pacetamidobenzyl)isoquinoline-4-carboxylate Ethyl 1,3(2H,4H )-Dioxo-2-(ohydroxybenzyl)isoquinoline-4-carboxy1ate EXAMPLE XXII 1,3 2H,4H )-Dioxo-2-methylisoquinoline-4-(N,N- tetramethylene)carboxamide A solution of ethyl l,3(2H,4H)-dioxo-2- methylisoquinoline-4-carboxylate (6.2 g., 0.025 mole) and pyrrolidine (1.8 g., 0.026 mole) in 100 ml. of xy- EXAMPLE XXIII The procedure of Example XXII was repeated, using equivalent amounts of appropriate amines in place of said pyrrolidine, to produce the following compounds:

Anal: Calcd Found R R X M.p.,C C H N C H N H H 2',5-diCl 242-243(dec.) 55.03 2.89 8.02 54.77 2.90 8.01 H H 3',4diCH 245-246(dec.) 70.11 5.23 9.09 70.00 5.22 8.79 H H 3 -diCl 239-241(dec.) 55.03 2.89 8.02 55.28 2.93 8.29 H H 2',5diOCH 197-198(dec.) 63.52 4.74 8.23 63.26 4.65 8.15 CH CH H 160162 70.1 1 5.23 9.09 69.86 5.22 9.06 CH CH 4-C1 156-158 63.07 4.41 8.17 62.76 4.46 8.18 CH; H 4'-Br 227-228(dec.) 54.71 3.51 7.51 54.96 3.45 7.45 CH H 4"F 221-222(dec.) 65.38 4.19 8.97 65.02 4.17 9.01 CH H 4-CF 210-211(dec.) 59.67 3.62 7.73 59.99 3.65 7.87 CH H 2',3'-diCl 217-219(dec.) 56.21 3.33 7.71 56.44 3.36 7.92 CH H 2,4-diCl 204-205(dec.) 56.21 3.33 7.71 56.54 3.38 7.95 CH H 2' -COOC H 121L130 65.56 4.95 7.65 65.42 5.04 7.63 CH H 4-COOC H 229-230(dec.) 65.56 4.95 7.65 65.57 4.89 7.70 CH H 5'-Cl-2-OCH-, 208.5209.5(dec.) 60.25 4.21 7.81 60.37 4.81 7.94 CH H 3 5'-diCl 228-229.5(dec.) 56.21 3.33 7.71 55.97 3.16 7.75 CH H 3',5-diOCH 209-210(dec.) 64.40 5.12 7.91 64.41 5.19 8.34 CH H 2',6'diCH 250(dec.) 70.79 5.63 8.69 70.91 5.79 8.91 CH H 2OCH;,-5- 212.5214(dec.) 67.44 5.36 8.28 67.44 5.50 8.40

-CH CH H 2',4diCH 227-228(dec.) 70.79 5.63 8.69 70.84 5.52 8.68 CH H 2',5diCH 243.5-244(dec.) 70.79 5.63 8.69 70.82 5.36 8.71 CH H 3-Cl-4'-CH 213-214(dec.) 63.07 4.41 8.17 63.31 4.38 8.15 CH H 3'COCH 177-178(dec.) 67.85 4.80 8.33 67.55 4.83 8.52 CH H 3'-C1-2'-CH 240240.5(dec.) 63.07 4.41 8.17 63.14 4.34 8.17 CH H 3',5-diCH 253-254(dec.) 70.79 5.63 8.69 70.52 5.78 8.77 CH H 2-Cl-4-CH;, 202.5-204(dec.) 63.07 4.41 8.17 63.23 4.38 8.15 CH H 2'CH 4- 213.52l4(dec.) 67.44 5.36 8.28 67.14 5.41 8.17

'-OCH CH H 4'-Cl-2'-CH 237-238(dec.) 63.07 4.41 8.17 62.88 4.37 8.29 CH H 2'-Cl-5 '-CF-, 205206(dec.) 54.49 3.05 7.06 54.65 3.12 7.1 1 H H 2',4'-diOCH 223-225(dec.) 63.52 4.74 8.23 63.75 4.69 8.51 H H 4'-F 242-244(dec.) 64.42 3.72 9.39 64.55 3.78 9.61 H H 4'-CF;, 250-251(dec.) 58.62 3.18 8.05 58.89 3.25 8.41 H H 4-Br 246-248(dec.) 53.50 3.09 7.80 53.79 3.04 7.90

lene was refluxed for 4 hours, during which time solvent was distilled off until the temperature of solvent vapors in the distilling head was within two degrees of the temperature of the reaction mixture. The volume of the reaction mixture was maintained by occasional ad- EXAMPLE XXIV The procedure of Example XXII is repeated, using equivalent amounts of appropriate amines in place of 5 said pyrrolidine, to produce the following compounds:

25 EXAMPLE XXVIII 2-Isopropyl-6,7-dimethylisoquinoline-l ,3(2I-l,4H)-

dione A mixture of 4,5-dimethylhombphthalic acid (104 g., 5

0.5 mole) and isopropylamine (59 g., 1 mole) is heated by an oil bath until molten for 90 minutes. The hot mixture is then poured into 600 ml. of ethanol, treated with carbon black and filtered. The mixture is concentrated to about 300 ml. and slowly cooled to room tempera- 10 ture. 2-lsopropyl-6,7-dimethylisoquinolinel,3(2H,4H)-dione precipitates and is collected by filtration.

EXAMPLE XXIX The following products are prepated by the procedure of Example XXVI by substituting an appropriate amine in place of said m-chloroaniline and an appropriately substituted homophthalic acid in place of said 4- chlorohomophthalic acid:

EXAMPLE xxx 7-Chloro-2-methyl-1,3(2I-l,4H)-dioxoisoquinoline-4- carboxarnide EXAMPLE XXXI The procedure of Example XXX is repeated, using equivalent amounts of the products of Examples XXVI XXIX in place of said 7-chloro-2-methylhexyl hydrogen 7-chloro cyclopropyl -methoxy 7-methoxy cyclohexyl hydrogen 7-methoxy ro ar 1 6-methox h dro en ffiryI S-nitro y hydrogen 2'-tetrahydrofuryl 6-fluoro S-propyl furfuryl S-nitro B-nitro tetrahydrofurfuryl hydrogen 7-amino methoxy 6-chloro 7-chloro hydroxy 6-methyl 7-methyl benzyloxy hydrogen 7-chloro p eny 6-chloro 7chloro o-fluorophenyl -methylsulfonyl 7-methylsulfonyl p-bromophenyl hydrogen 7-trifluoromethylsulfonyl p-ethoxyphenyl S-methyl 7-dimethylsulfonamido m-isopropylphenyl 6-bromo S-acetamido o-methylphenyl S-hydroxy 8-hydroxy m-trifluoromethylphenyl -fluoro hydrogen m-nitrophenyl hydrogen 8-chloro p-amino henyl S-bromo hydrogen o-methy sulfonylphenyl o ethoxy hydrogen m-trifluoromethylsulfonylphenyl hydrogen 7-isopropyl m-dimethylsulfonamidophenyl hydrogen 7-amino p-acetamidophenyl hydrogen 7-trifluoromethyl o-hydroxyphenyl 6-methylsulfonyl 7-chloro benzyl hydrogen 7-ethoxy o-fluorobenzyl hydrogen 7-fluoro p-bromobenzyl hydrogen 7-chloro p-ethoxybenzyl hydrogen 8-bromo m-isopropylbenzyl hydrogen 7-ethoxy o-methylbenzyl hydrogen 6-isopropyl m-trifluoromethylbenzyl hydrogen 6-trifluoromethyl m-nitrobenzyl hydrogen S-nitro p-aminobenzyl hydrogen 6-amino o-methylsulfonylbenzyl hydrogen 7-methylsulfonyl m-trifluoromethylsulfonylbenzyl hydrogen 7-trifluoromethylsulfonyl m-dimethylsulfonamidobenzyl hydrogen 7-dimethylsulfonamido p-acetamidobenzyl hydrogen -acetamido p-acetamidobenzyl hydrogen 7-hydroxy o-hydroxybenzyl hydrogen 7-chloro Anal.: Calcd. Found R, X X X M.p.,C. C H N C H N CH;, 2--OCH H 7-OCH l92-l94 64.40 5.12 7.91 64.44 5.09 7.93 CH 2'-Cl H 7OCH 2l6,52l7(dec.) 60.25 4.21 7.81 60.48 4.24 8.04 CH 2-Cl 6OCH 7OCH 247-249(dec.) 58.70 4.41 7.21 58.60 4.411 7.35 H H 6OCH 7OCH;, 251-252(dec.) 63.52 4.74 8.23 63.56 4.82 8.19 H H H 7-Cl 224-226(dec.) 61.06 3.52 8.90 61.06 3.47 8.85 H H H 7OCH 27l273(dec.) 65.80 4.55 9.03 65.52 4.57 9.16

EXAMPLE XXXIV The procedure. of Example XXXIII is repeated, using equivalent amounts of appropriately substituted substrates to produce the following compounds:

l dioxoisoquinoline (5.5 g., 0.025 mole) and triethylamine (2.6 g., 0.026 mole) in ml. of dimethylsulfoxide was added dropwise, over a five minute period, a solution of ethylisocyanate (1.86 g., 0.026 mole) in 10 ml. of dimethylsulfoxide. After stirring for 2 hours, the so- R1 X1 X2 neopentyl acetyl hydrogen 7-chloro hydrogen butyryl 6-methoxy 7-methoxy phenyl benzoyl S-nitro hydrogen m-trifluoromethylbenzyl 3-nitrophenyl 6-amino hydrogen methyl n-butyl 5-metl1yl S-methyl m-chlorophenyl benzoyl S-methyl hydrogen methyl carbethoxymethyl hydrogen 7-hydroxy methyl hydrogen 6-fluoro 8-propyl methyl 2-chloro 5-nitro S-nitro 4o methyl 3-chloro hydrogen 7-amino methyl 4chloro 6-chloro 7-chloro methyl 3methy1 6-methylsulfonyl 7methylsulfonyl methyl 4-methyl hydrogen 7-trifluoromethyl methyl Z-methoxy 6-bromo S-acetamido methyl 4-methoxy S-hjydroxy 8-hydroxy methyl Z-ethoxy hy rogen 7-isopropyl methyl 4-ethoxy 6-ethoxy 7-ethoxy m-chlorophenyl hydrogen 6-methylsulfony1 7-chloro benzy hydrogen hydrogen 8-bromo ally] hydrogen S-nitro hydrogen EXAMPLE XXXV To a stirred mixture of 6,7-dimet hoxy-l,3(2H,4H)

lution was poured into an excess of ice water containing 5 ml. of hydrochloric acid. The resulting precipitate was collected by filtration, washed with water, dried and recrystallized from acetonitrile to give 6,7- dimethoxy-l ,3(2H,4H)-dioxoisoquinoline-4-(N-ethyl)- carboxamide, m.p. 255257C. (dec.).

Anal. Calcd. for C H N O C, 57.53; H, 5.52; N, 9.59. Found: C, 57.55; H, 5.65; N, 9.34.

EXAMPLE XXXVI The procedure of Example XXXV was repeated, using equivalent amounts of appropriate substrates in place of said 6,7-dimethoxy-l ,3(2H,4H dioxoisoquinoline and ethylisocyanate, to produce the following compounds:

0 NH-C H I Anal: Calcd Found R, X X M.p.C. H C H N CH;, H 7-Cl 2l82l9(dec.) 55.62 4.67 9.98 55.69 4.71 9.93 CH 6OCH 7--OCH 250251(dec.) 58.81 5.92 9.15 59.12 5.93 9.01 H H 7-C1 237-238(dec.) 54.04 4.16 10.51 54.01 4.37 10.59

, X X H 1 pm g-O Anal: Calcd Found R, X X X- M.p.C. C H N C H N CH;, 2,5-diCl H 7OCH 210-211 54.98 3.59 7.13 55.08 3.76 7.17 CH 2CH,, 6-OCH,-, 7OCH 242-243(dec.) 65.20 5.47 7.61 65.33 5.39 7.71 H 4-Cl 6-OCH 7OCH 260-261(dec.) 57.68 4.03 7.48 57.76 4.09 7.53 H 4-C1 H 7-Cl 240241(dec.) 55.03 2.89 8.02 55.12 2.83 8.26 H H H 7OCH 271273(dec.) 65.80 4.55 9.03 65.52 4.57 9.16 H 4-Cl H 7OCH 280-282(dec.) 59.22 3.80 8.13 59.15 3.71 8.06

EXAMPLE XXXVI] The procedure of Example XXXV is repeated, using equivalent amounts of appropriate substrates in place 2 of said 6,7-dimethoxy-1,3(2H,4H)-dioxoisoquinoline and ethylisocyanate, to produce the following compounds:

EXAMPLE XXXVIII 7-Methoxy-2-methyl-1,3(2H,4H)-dioxoisoquinoline-4- (N-benzyl)carboxamide A mixture of 7 1,3 2H ,4H )-dioxoisoquinoline-4-carboxanilide 2'-chloro-7-methoxy-2-methylg., 0.025 mole), prepared as in Example XXXIII, and benzylamine (2.7 g., 0.025 mole) in 100 ml. of xylene 0 is refluxed for 6 hours, after which time the mixture is allowed to cool. The resulting precipitate is collected by filtration, dried and recrystallized from xylene, giving the desired 7-methoxy-2-methyl-1,3(2H,4H)- dioxoisoquinoline-4-(N-benzyl)carboxamide.

EXAMPLE XXXIX The procedure of Example XXXVIII is repeated, using equivalent amounts of appropriately substituted o-chlorocarboxanilides and amines, to produce the following compounds:

- 1 ,3 2H ,4H )-dioxoisoquinoline-4-carboxanilide (17.9 g., 0.05 mole), prepared as in Example XXXIII, in

ml. of absolute ethanol is refluxed for 4 hours. The

lected by filtration and dried to give the desired ethyl 5 7-methoxy-2-methyll ,3( 2H ,4 )-dioxoisoquinoline-4- carboxylate.

EXAMPLE XLI The procedure of Example XL is repeated, using 10 equivalent amounts of appropriately substituted carboxanilides and appropriate alcohol in place of said 0- chlorocarboxanilide and ethanol, to produce the following compounds:

A solution of ethyl 7-methoxy-2-methyl-1,3(2H,4H)- dioxoisoquinoline-4-carboxylate (6.9 g., 0.025 mole), prepared as in Example XL, and pyrrolidine (1.8 g., 0.026 mole) in 100 ml, of xylene is refluxed for 4 hours, during which time solvent is distilled off until the temperature of solvent vapors in the distilling head are within two degrees of the temperature of the reaction mixture. The volume of the reaction mixture is maintained by occasional addition of xylene. The mixture is then allowed to cool and the resulting crystals are collected by filtration, dried and recrystallized from acetonitrile to give the desired 7-methoxy-2-methyl- 1,3 2H,4H )-isoquinoline-4-(N,N-tetramethylene)carboxamide.

r .J 0 R5 X v 1 X l 2 0 R1 R5 1 X2 hydrogen ethyl 6-chloro 7-chloro hexyl methyl hydrogen 7-chloro cyclopropyl methyl o-methoxy 7-methoxy cyclohexyl methyl hydrogen 7-methoxy propargyl methyl 6-methoxy hydrogen 2'-furyl methyl S-nitro hydrogen 2'-tetrahydrofurfuryl i-propyl 6-fluoro 8-propyl furfuryl i-propyl S-nitro B-nitro tetrahydrofurfuryl'. i-propyl hydrogen 7-amino methoxy i-propyl 6-chloro 7-chloro hydroxy i-propyl 6-methyl 7-methyl benzyloxy i-propyl hydrogen 7-chloro phenyl i-propyl 6-chloro 7-chloro o-fluorophenyl i-propyl 6-methylsulfonyl 7-methylsulfonyl p-bromophenyl i-propyl hydrogen 7-trifluoromethylsulfonyl p-ethoxyphenyl n-hexyl S-methyl 7-dimethylsulfonamido m-isopropylphenyl n-hexyl 6-bromo S-acetamido o-methylphenyl n-hexyl S-hydroxy 8-hydroxy m-trifluoromethylphenyl n-hexyl 6-fluoro hydrogen m-nitrophenyl n-hexyl hydrogen 8-chloro p-aminophenyl i-butyl S-bromo hydrogen o-methylsulfonylphenyl i-butyl 6-ethoxy hydrogen m-trifluoromethylsuli-butyl hydrogen 7-isopropyl fonylphenyl m-dimethylsulfonamidoi-butyl hydrogen 7-amino phenyl p-acetamidophenyl i-butyl hydrogen 7-trfluoromethyl o-hydroxyphenyl ethyl 6-methylsulfonyl 7-chloro benzyl ethyl hydrogen 7-ethoxy o-fluorobenzyl ethyl hydrogen 7-fluoro p-bromobenzyl ethyl hydrogen 7-chloro p-ethoxybenzyl ethyl hydrogen 8-bromo m-isopropylbenzyl ethyl hydrogen 7-ethoxy o-methylbenzyl ethyl hydrogen fi-isopropyl m-trifluoromethylbenzyl ethyl hydrogen -trifluoromethyl m-nitrobenzyl ethyl hydrogen S-nitro p-arninobenzyl ethyl hydrogen 6-amino o-methylsulfonylbenzyl ethyl hydrogen 7-methylsulfonyl m-trifluoromethylsulethyl hydrogen 7-trifluoromethylsulfonyl fonylbenzyl m-dimethylsulfonamidoethyl hydrogen 7-dimethylsulfonamido benzyl p-acetamidobenzyl ethyl hydrogen -acetamido p-acetamidobenzyl ethyl hydrogen 7-hydroxy o-hydroxybenzyl hydrogen 7-chloro Y EXAMPLE'XLII 7-Methoxy-2-methyl- 1 ,3 2l-l,4l-l )-dioxoisoquinoline-4- N,N-tetramethylene)carboxamide EXAMPLE XLlll duce the following compounds: 

1. A COMPOUND OF THE FORMULA
 2. A compound of the formula
 3. A compound of formula
 4. The compound of claim 3 wherein R3 is phenyl.
 5. The compound of claim 3 wherein R3 is p-chlorophenyl.
 6. The compound of claim 2 wherein R3 is p-chlorophenyl.
 7. The compound of claim 3 wherein R3 is p-fluorophenyl.
 8. The compound of claim 3 wherein R3 is 2,4-dichlorophenyl. 